System and method for electrically determining position and detachment of an implantable device

Abstract

A method and system for positioning a detachment zone and an implant, such as a vaso-occlusive coil or a stent, attached thereto in a body. A catheter is inserted within a vascular cavity in the body. The implant is attached to a distal end of a delivery member using a temporary connection, such as an electrolytic, mechanical, hydraulic, heat-sensitive or Radio Frequency (RF) sensitive connection, with an insulation member between the wire and the implant. The delivery member, temporary connection and implant are advanced through the catheter. An electrical condition, such as current, voltage and impedance, related to the position of the temporary connection in the catheter is monitored with an electrical measurement device or sensor. The electrical condition changes when the temporary connection reaches or exits a predetermined location, for example, the distal end of the catheter and contacts a conductive component of the body, such as blood in an aneurysm.

1 . A method of positioning an implant in a body, comprising: 
 providing the implant, a delivery member, a temporary connection, and a catheter,    inserting the catheter within a vascular cavity in the body;    attaching the implant to a distal end of the delivery member with the temporary connection;    advancing the delivery member, the temporary connection and the implant through a proximal end of the catheter; and    monitoring an electrical condition related to a position of the temporary connection in the catheter, the electrical condition changing when the temporary connection reaches a predetermined location.    
     
     
         2 . The method of  claim 1 , monitoring the electrical condition further comprising monitoring a current.  
     
     
         3 . The method of  claim 1 , monitoring the electrical condition further comprising monitoring a voltage.  
     
     
         4 . The method of  claim 1 , monitoring the electrical condition further comprising monitoring an impedance.  
     
     
         5 . The method of  claim 1 , further comprising generating an output signal in response to the changed electrical condition.  
     
     
         6 . The method of  claim 5 , generating the output signal further comprising generating a visual signal.  
     
     
         7 . The method of  claim 5 , generating the output signal further comprising generating an audio signal.  
     
     
         8 . The method of  claim 5 , further comprising 
 breaking the temporary connection and    detaching the implant from the distal end of the delivery member.    
     
     
         9 . The method of  claim 8 , further comprising providing the output signal to a user, the temporary connection being broken in response to user input.  
     
     
         10 . The method of  claim 8 , further comprising providing the output signal to a controller, the temporary connection being broken in response to the controller.  
     
     
         11 . The method of  claim 8 , breaking the temporary connection further comprising breaking an electrolytic connection.  
     
     
         12 . The method of  claim 11 , breaking the electrolytic connection further comprising: 
 providing a current through the delivery member and the temporary connection; and    corroding a portion of the temporary connection.    
     
     
         13 . The method of  claim 12 , corroding the portion of the temporary connection further comprising corroding a stainless steel portion of the delivery member that is exposed to blood in the vascular cavity.  
     
     
         14 . The method of  claim 8 , breaking the temporary connection further comprising breaking a mechanical connection.  
     
     
         15 . The method of  claim 8 , breaking the temporary connection further comprising breaking the temporary connection with heat.  
     
     
         16 . The method of  claim 8 , breaking the temporary connection further comprising breaking the temporary connection with Radio Frequency (RF) radiation.  
     
     
         17 . The method of  claim 8 , breaking the temporary connection further comprising breaking the temporary connection hydraulically.  
     
     
         18 . The method of  claim 8 , further comprising removing the delivery member and the catheter from the vascular cavity after detaching the implant.  
     
     
         19 . The method of  claim 1 , further comprising insulating the implant from the temporary connection.  
     
     
         20 . The method of  claim 1 , the electrical condition changing when the temporary connection reaches the distal end of the catheter.  
     
     
         21 . The method of  claim 1 , the electrical condition changing when the temporary connection exits the distal end of the catheter.  
     
     
         22 . The method of  claim 1 , providing the implant further comprising providing a vaso-occlusive implant.  
     
     
         23 . The method of  claim 1 , providing the implant further comprising providing a coil.  
     
     
         24 . The method of  claim 23 , providing the coil further comprising providing a Guglielmi Detachable Coil (GDC).  
     
     
         25 . The method of  claim 23 , providing the coil further comprising providing a coil including platinum.  
     
     
         26 . The method of  claim 23 , providing the coil further comprising providing a coil coated with a bio-reactive material.  
     
     
         27 . The method of  claim 23 , providing the coil further comprising providing a bio-reactive coil.  
     
     
         28 . The method of  claim 23 , providing the coil further comprising providing a non-bioreactive polymer coil.  
     
     
         29 . A system for positioning an implant in a body, comprising: 
 a catheter having a proximal end and a distal end, the catheter being inserted into a vascular cavity in the body;    a delivery member;    a temporary connection joining the implant and a distal end of the delivery member; and    an electrical measurement device,    the delivery member, the temporary connection and the implant being advanced through the catheter, the electrical measuring device monitoring an electrical condition related to a position of the temporary connection in the catheter, the electrical condition changing when the temporary connection reaches a predetermined location.    
     
     
         30 . The system of  claim 29 , the delivery member comprising a delivery wire.  
     
     
         31 . The system of  claim 29 , the delivery member comprising a tubular body.  
     
     
         32 . The system of  claim 29 , the temporary connection comprising an electrolytic connection.  
     
     
         33 . The system of  claim 32 , further comprising a power supply, the electrolytic connection being broken by current provided by the power supply through the delivery member and the temporary connection, the current corroding a portion of the temporary connection.  
     
     
         34 . The system of  claim 33 , the portion of the temporary connection being corroded comprising a stainless steel portion of the delivery member that is exposed to blood in the vascular cavity.  
     
     
         35 . The system of  claim 33 , the electrical monitoring device being included in the power supply.  
     
     
         36 . The system of  claim 33 , the electrical monitoring device being separate from the voltage supply.  
     
     
         37 . The system of  claim 29 , the temporary connection comprising breaking a temporary mechanical connection.  
     
     
         38 . The system of  claim 29 , the temporary connection comprising a temporary connection that is broken by application of heat.  
     
     
         39 . The system of  claim 29 , the temporary connection comprising a temporary connection that is broken with application of Radio Frequency (RF) radiation.  
     
     
         40 . The system of  claim 29 , the temporary connection comprising a temporary connection that is hydraulically broken.  
     
     
         41 . The system of  claim 29 , the electrical condition comprising a current.  
     
     
         42 . The system of  claim 29 , the electrical condition comprising a voltage.  
     
     
         43 . The system of  claim 29 , the electrical condition comprising an impedance.  
     
     
         44 . The system of  claim 29 , the implant comprising a vaso-occlusive implant.  
     
     
         45 . The system of  claim 44 , the implant comprising a coil.  
     
     
         46 . The system of  claim 45 , the coil comprising a Guglielmi Detachable Coil (GDC).  
     
     
         47 . The system of  claim 45 , the coil including platinum.  
     
     
         48 . The system of  claim 45 , the coil having a bio-reactive material coating.  
     
     
         49 . The system of  claim 45 , the coil comprising a bio-reactive coil.  
     
     
         50 . The system of  claim 45 , the coil comprising a non-bio-reactive polymer coil.  
     
     
         51 . The system of  claim 29 , the implant comprising a stent.  
     
     
         52 . The system of  claim 29 , the implant comprising a filter.  
     
     
         53 . The system of  claim 29 , the electrical measurement device generating an output signal in response to the changed electrical condition.  
     
     
         54 . The system of  claim 53 , the output signal comprising a visual signal.  
     
     
         55 . The system of  claim 53 , the output signal comprising an audio signal.  
     
     
         56 . The system of  claim 53 , the output signal being provided to a user and the temporary connection being broken in response to user input.  
     
     
         57 . The system of  claim 53 , the output signal being provided to a controller, the temporary connection being broken in response to the controller.  
     
     
         58 . The system of  claim 29 , further comprising an insulative member between the implant and the temporary connection.  
     
     
         59 . The system of  claim 29 , the predetermined position comprising the distal end of the catheter.  
     
     
         60 . The system of  claim 59 , the electrical condition changing when the temporary connection reaches the distal end of the catheter.  
     
     
         61 . The system of  claim 59 , the electrical condition changing when the temporary connection exits the distal end of the catheter.  
     
     
         62 . The system of  claim 29 , electrical measurement device comparing a reference current with a second current that is generated when the temporary connection reaches the predetermined location.  
     
     
         63 . The system of  claim 29 , the electrical measurement device including a comparison circuit that compares a threshold current to a current measured by the electrical measurement device, the comparison circuit generating an output indicating whether the temporary connection reaches a predetermined location.  
     
     
         64 . The system of  claim 29 , further comprising a conductive wire connected between the electrical measurement device and the distal end of the catheter, the electrical monitoring device detecting an electrical condition related to a position of the temporary connection in the catheter through the conductive wire.  
     
     
         65 . The system of  claim 64 , the conductive wire being inserted through the catheter.  
     
     
         66 . The system of  claim 29 , the electrical monitoring device comprising a volt/current meter.